Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
1.
Nat Cell Biol ; 25(11): 1637-1649, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37945831

ABSTRACT

Epigenetic dysregulation is a prominent feature in cancer, as exemplified by frequent mutations in chromatin regulators, including the MLL/KMT2 family of histone methyltransferases. Although MLL1/KMT2A activity on H3K4 methylation is well documented, their non-canonical activities remain mostly unexplored. Here we show that MLL1/KMT2A methylates Borealin K143 in the intrinsically disordered region essential for liquid-liquid phase separation of the chromosome passenger complex (CPC). The co-crystal structure highlights the distinct binding mode of the MLL1 SET domain with Borealin K143. Inhibiting MLL1 activity or mutating Borealin K143 to arginine perturbs CPC phase separation, reduces Aurora kinase B activity, and impairs the resolution of erroneous kinetochore-microtubule attachments and sister-chromatid cohesion. They significantly increase chromosome instability and aneuploidy in a subset of hepatocellular carcinoma, resulting in growth inhibition. These results demonstrate a non-redundant function of MLL1 in regulating inner centromere liquid condensates and genome stability via a non-canonical enzymatic activity.


Subject(s)
Chromosomal Proteins, Non-Histone , Mitosis , Humans , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/metabolism , HeLa Cells , Centromere/genetics , Centromere/metabolism , Cell Cycle Proteins/genetics , Genomic Instability , Aurora Kinase B/genetics , Aurora Kinase B/metabolism
2.
Nat Commun ; 12(1): 2953, 2021 05 19.
Article in English | MEDLINE | ID: mdl-34012049

ABSTRACT

Recent cryo-EM structures show the highly dynamic nature of the MLL1-NCP (nucleosome core particle) interaction. Functional implication and regulation of such dynamics remain unclear. Here we show that DPY30 and the intrinsically disordered regions (IDRs) of ASH2L work together in restricting the rotational dynamics of the MLL1 complex on the NCP. We show that DPY30 binding to ASH2L leads to stabilization and integration of ASH2L IDRs into the MLL1 complex and establishes new ASH2L-NCP contacts. The significance of ASH2L-DPY30 interactions is demonstrated by requirement of both ASH2L IDRs and DPY30 for dramatic increase of processivity and activity of the MLL1 complex. This DPY30 and ASH2L-IDR dependent regulation is NCP-specific and applies to all members of the MLL/SET1 family of enzymes. We further show that DPY30 is causal for de novo establishment of H3K4me3 in ESCs. Our study provides a paradigm of how H3K4me3 is regulated on chromatin and how H3K4me3 heterogeneity can be modulated by ASH2L IDR interacting proteins.


Subject(s)
DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Histone-Lysine N-Methyltransferase/metabolism , Myeloid-Lymphoid Leukemia Protein/metabolism , Nuclear Proteins/chemistry , Nuclear Proteins/metabolism , Transcription Factors/chemistry , Transcription Factors/metabolism , Animals , Cell Line , Chromatin/metabolism , Cryoelectron Microscopy , DNA-Binding Proteins/genetics , Histones/metabolism , Human Embryonic Stem Cells/metabolism , Humans , In Vitro Techniques , Intrinsically Disordered Proteins/chemistry , Intrinsically Disordered Proteins/metabolism , Magnetic Resonance Spectroscopy , Mice , Models, Molecular , Mouse Embryonic Stem Cells/metabolism , Nuclear Proteins/genetics , Nucleosomes/metabolism , Nucleosomes/ultrastructure , Protein Conformation , Protein Interaction Domains and Motifs , Scattering, Small Angle , Transcription Factors/genetics , X-Ray Diffraction
3.
J Biol Chem ; 296: 100235, 2021.
Article in English | MEDLINE | ID: mdl-33376138

ABSTRACT

Epigenetic mechanisms that alter heritable gene expression and chromatin structure play an essential role in many biological processes, including liver function. Human MOF (males absent on the first) is a histone acetyltransferase that is globally downregulated in human steatohepatitis. However, the function of MOF in the liver remains unclear. Here, we report that MOF plays an essential role in adult liver. Genetic deletion of Mof by Mx1-Cre in the liver leads to acute liver injury, with increase of lipid deposition and fibrosis akin to human steatohepatitis. Surprisingly, hepatocyte-specific Mof deletion had no overt liver abnormality. Using the in vitro coculturing experiment, we show that Mof deletion-induced liver injury requires coordinated changes and reciprocal signaling between hepatocytes and Kupffer cells, which enables feedforward regulation to augment inflammation and apoptotic responses. At the molecular level, Mof deletion induced characteristic changes in metabolic gene programs, which bore noticeable similarity to the molecular signature of human steatohepatitis. Simultaneous deletion of Mof in both hepatocytes and macrophages results in enhanced expression of inflammatory genes and NO signaling in vitro. These changes, in turn, lead to apoptosis of hepatocytes and lipotoxicity. Our work highlights the importance of histone acetyltransferase MOF in maintaining metabolic liver homeostasis and sheds light on the epigenetic dysregulation in liver pathogenesis.


Subject(s)
Histone Acetyltransferases/genetics , Inflammation/metabolism , Liver Diseases/genetics , Liver/injuries , Nitric Oxide/genetics , Apoptosis/genetics , Chromatin/genetics , Epigenesis, Genetic/genetics , Fatty Liver/genetics , Fatty Liver/metabolism , Fatty Liver/pathology , Gene Deletion , Gene Expression Regulation/genetics , Hepatocytes/metabolism , Hepatocytes/pathology , Histone Acetyltransferases/chemistry , Humans , Inflammation/genetics , Inflammation/pathology , Lipids/adverse effects , Lipids/genetics , Liver/metabolism , Liver/pathology , Liver Diseases/metabolism , Liver Diseases/pathology , Macrophages/metabolism , Macrophages/pathology , Nitric Oxide/metabolism , Signal Transduction/genetics
4.
Biochim Biophys Acta Gene Regul Mech ; 1863(7): 194561, 2020 07.
Article in English | MEDLINE | ID: mdl-32304759

ABSTRACT

In eukaryotes, histone H3K4 methylation by the MLL/SET1 family histone methyltransferases is enriched at transcription regulatory elements including gene promoters and enhancers. The level of H3K4 methylation is highly correlated with transcription activation and is one of the most frequently used histone post-translational modifications to predict transcriptional outcome. Recently, it has been shown that rearrangement of the cellular landscape of H3K4 mono-methylation at distal enhancers precedes cell fate transition and is used for identification of novel regulatory elements for development and disease progression. Similarly, broad H3K4 tri-methylation regions have also been used to predict intrinsic tumor suppression properties of regulator regions in a variety of cellular models. Understanding the regulation for how H3K4 methylation is deposited and regulated is of paramount importance. In this review, we will discuss new findings on how the MLL/SET1 family enzymes are regulated on chromatin and their potential functional and regulatory implications. This article is part of a Special Issue entitled: The MLL family of proteins in normal development and disease edited by Thomas A Milne.


Subject(s)
Histone-Lysine N-Methyltransferase/metabolism , Myeloid-Lymphoid Leukemia Protein/metabolism , Animals , Histone Code , Histone-Lysine N-Methyltransferase/chemistry , Humans , Myeloid-Lymphoid Leukemia Protein/chemistry , Nucleosomes/chemistry , Nucleosomes/metabolism
5.
Nat Commun ; 11(1): 1165, 2020 02 27.
Article in English | MEDLINE | ID: mdl-32109228

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

6.
Nat Commun ; 10(1): 5540, 2019 12 05.
Article in English | MEDLINE | ID: mdl-31804488

ABSTRACT

Mixed lineage leukemia (MLL) family histone methyltransferases are enzymes that deposit histone H3 Lys4 (K4) mono-/di-/tri-methylation and regulate gene expression in mammals. Despite extensive structural and biochemical studies, the molecular mechanisms whereby the MLL complexes recognize histone H3K4 within nucleosome core particles (NCPs) remain unclear. Here we report the single-particle cryo-electron microscopy (cryo-EM) structure of the NCP-bound human MLL1 core complex. We show that the MLL1 core complex anchors to the NCP via the conserved RbBP5 and ASH2L, which interact extensively with nucleosomal DNA and the surface close to the N-terminal tail of histone H4. Concurrent interactions of RbBP5 and ASH2L with the NCP uniquely align the catalytic MLL1SET domain at the nucleosome dyad, thereby facilitating symmetrical access to both H3K4 substrates within the NCP. Our study sheds light on how the MLL1 complex engages chromatin and how chromatin binding promotes MLL1 tri-methylation activity.


Subject(s)
Cryoelectron Microscopy/methods , Histone-Lysine N-Methyltransferase/metabolism , Histones/metabolism , Myeloid-Lymphoid Leukemia Protein/metabolism , Nucleosomes/metabolism , Animals , Cell Nucleus/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/ultrastructure , Humans , Lysine/metabolism , Methylation , Mutation , Myeloid-Lymphoid Leukemia Protein/genetics , Myeloid-Lymphoid Leukemia Protein/ultrastructure , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Nucleosomes/ultrastructure , Protein Binding , Transcription Factors/genetics , Transcription Factors/metabolism , Xenopus laevis
7.
Int J Clin Exp Pathol ; 11(11): 5525-5535, 2018.
Article in English | MEDLINE | ID: mdl-31949640

ABSTRACT

The tumor suppressor liver kinase B1 (LKB1), a highly conserved and ubiquitously expressed protein kinase, plays a critical role in tumorigenesis. LKB1 has recently been identified in tumorigenesis of several cancers including lung cancer, breast cancer, and pancreatic cancer. However, the role of LKB1 in hepatocellular carcinoma (HCC) remains unclear. Herein, we examined the expression levels of LKB1 in HCC patients and cell lines by quantitative real-time PCR (qRT-PCR) and western blot analysis. Furthermore, LKB1 protein expression was analyzed in archived paraffin-embedded HCC tissues using immunohistochemistry (IHC), and its association with overall survival was shown in statistical analysis. In vitro assays, including RNAi studies, were performed to further explore the role of LKB1 in tumor progression in HCC cell lines. Our results revealed that the expression of LKB1 was lower in HCC tissue and cell lines than in corresponding adjacent normal tissue and normal human liver cell line (HL7702). Moreover, HCC patients with low LKB1 expression had advanced clinical stage and worse prognosis than those with higher LKB1 expression. Furthermore, siRNA-mediated knockdown of LKB1 resulted in enhanced cell proliferation, migration, and invasion of HCC cells. Additionally, the expression level of LKB1 positively correlated with E-cadherin levels, wherein siRNA-transfected cells exhibited significantly decreased levels of E-cadherin, while phosphorylated p38 and vimentin levels were enhanced. Inhibition of p38 MAPK signaling was capable of reversing E-cadherin up-regulation and vimentin down-regulation. In all, our results indicate that LKB1 acts as a tumor suppressor gene, which may inhibit EMT through the p38 MAPK signaling pathway involved in HCC progression.

8.
China Pharmacy ; (12): 530-533, 2018.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-704621

ABSTRACT

OBJECTIVE: To investigate the effects of Yupingfeng granules on immune function and related indexes of children with allergic rhinitis (AR) complicated with bronchial asthma (BA). METHODS: Clinical information of 101 children with AR complicated with BA during Feb. 2014-Sept. 2017 were analyzed retrospectively, and they were divided into control group (47 cases) and observation group (54 cases) according to treatment plan. Control group was given Salmeterol xinafoate and fluticasone propionate powder for inhalation through mouth, one inhalation, twice a day+Mometasone furoate nasal spray 50 μg each nostril. Observation group was additionally given Yupingfeng granules 5 g orally, 3 times a day, for consecutive 2 weeks, drug withdrawal at 2 weeks interval, recycled 3 times. Both groups received treatment for consecutive 3 months. Clinical symptom and sign scores, the levels of T-lymphocyte subgroup (CD4+, CD8+, CD4+/CD8+), IL-4, IFN-γ and IgE before and after treatment, the occurrence of ADR were observed in 2 groups. RESULTS: Before treatment, there was no statistical significance in clinical symptom and sign scores, levels of T-lymphocyte subgroup, serum levels of IL-4, IFN-γ or IgE between 2 groups (P>0. 05). After treatment, clinical symptom and sign scores, CD4+, CD4+/CD8+, serum levels of IL-4 and IgE in 2 groups were all significantly lower than before treatment; observation group was significantly lower than control group. CD8+ and serum levels of IFN-y in 2 groups after treatment were significantly higher than before treatment; observation group was significantly higher than control group, with statistical significance (P<0. 05). There was no statistical significance in the incidence of ADR between 2 groups (P>0. 05). CONCLUSIONS: Yupingfeng granules can effectively improve immune function of children with AR complicated with BA, and relieve clinical symptom without increasing the occurrence of ADR.

9.
J Biochem ; 161(6): 521-527, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-28158808

ABSTRACT

Protein arginine methyltransferases (PRMTs) catalyze the transfer of a methyl group from S-adenosylmethionine to arginine residues and are classified into two types: type I producing asymmetric dimethylarginine (ADMA) and type II producing symmetric dimethylarginine (SDMA). PRMTs have been shown to regulate many cellular processes, including signal transduction, transcriptional regulation and RNA processing. Since the loss-of-function mutation of PRMT1 and PRMT5, each of which is the predominant type I and II, respectively, causes embryonic lethality in mice, their physiological significance at the whole-body level remains largely unknown. Here, we show the morphological and functional phenotypes of single or double null alleles of prmt-1 and prmt-5 in Caenorhabditis elegans. The prmt-1;prmt-5 double mutants are viable, and exhibit short body length and small brood size compared to N2 and each of the single mutants. The liquid chromatography-tandem mass spectrometry analysis demonstrated that the levels of ADMA and SDMA were abolished in the prmt-1;prmt-5 double mutants. Both prmt-1 and prmt-5 were required for resistance to heat and oxidative stresses, whereas prmt-5 is not involved in lifespan regulation even when prmt-1 is ablated. This mutant strain would be a useful model animal for investigating the role of asymmetric and symmetric arginine dimethylation in vivo.


Subject(s)
Arginine/metabolism , Caenorhabditis elegans/enzymology , Caenorhabditis elegans/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Animals , Methylation
10.
Free Radic Biol Med ; 104: 118-128, 2017 03.
Article in English | MEDLINE | ID: mdl-28049024

ABSTRACT

The current consensus is that environmental electrophiles activate redox signal transduction pathways through covalent modification of sensor proteins with reactive thiol groups at low concentrations, while they cause cell damage at higher concentrations. We previously exposed human carcinoma A431 cells to the atmospheric electrophile 1,4-naphthoquinone (1,4-NQ) and found that heat shock protein 90 (HSP90), a negative regulator of heat shock factor 1 (HSF1), was a target of 1,4-NQ. In the study presented here, we determined whether 1,4-NQ activates HSF1. We also examined whether such redox signaling could be regulated by nucleophilic sulfur species. Exposure of A431 cells to 1,4-NQ covalently modified cellular HSP90, resulting in repression of the association between HSF1 with HSP90, thereby enhancing HSF1 translocation into the nuclei. Liquid chromatography-tandem mass spectrometry analysis with recombinant HSP90 revealed that the modifications site were Cys412 and Cys564. We found that HSF1 activation mediated by 1,4-NQ upregulated downstream genes, such as HSPA6. HSF1 knockdown accelerated 1,4-NQ-mediated cytotoxicity in the cells. While simultaneous treatment with reactive persulfide and polysulfide, Na2S2 and Na2S4, blocked 1,4-NQ-dependent protein modification and HSF1 activation in A431 cells, the knockdown of Cys persulfide producing enzymes cystathionine ß-synthase (CBS) and/or cystathionine γ-lyase (CSE) enhanced these phenomena. 1,4-NQ-thiol adduct and 1,4-NQ-S-1,4-NQ adduct were produced during the enzymatic reaction of recombinant CSE in the presence of 1,4-NQ. The results suggest that activation of the HSP90-HSF1 signal transduction pathway mediated by 1,4-NQ protects cells against 1,4-NQ and that per/polysulfides can diminish the reactivity of 1,4-NQ by forming sulfur adducts.


Subject(s)
HSP70 Heat-Shock Proteins/genetics , HSP90 Heat-Shock Proteins/metabolism , Heat Shock Transcription Factors/genetics , Naphthoquinones/administration & dosage , Cell Line, Tumor , Cell Nucleus/genetics , Cell Nucleus/metabolism , Chromatography, Liquid , Cysteine/metabolism , DNA-Binding Proteins/metabolism , Gene Expression Regulation/drug effects , HSP90 Heat-Shock Proteins/genetics , Humans , Naphthoquinones/metabolism , Oxidation-Reduction , Signal Transduction/drug effects , Sulfhydryl Compounds/metabolism , Sulfur/metabolism , Tandem Mass Spectrometry
11.
Mol Cell Biol ; 37(6)2017 03 15.
Article in English | MEDLINE | ID: mdl-27994012

ABSTRACT

Protein arginine methyltransferase 1 (PRMT-1) catalyzes asymmetric arginine dimethylation on cellular proteins and modulates various aspects of biological processes, such as signal transduction, DNA repair, and transcriptional regulation. We have previously reported that the null mutant of prmt-1 in Caenorhabditis elegans exhibits a slightly shortened life span, but the physiological significance of PRMT-1 remains largely unclear. Here we explored the role of PRMT-1 in mitochondrial function as hinted by a two-dimensional Western blot-based proteomic study. Subcellular fractionation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that PRMT-1 is almost entirely responsible for asymmetric arginine dimethylation on mitochondrial proteins. Importantly, isolated mitochondria from prmt-1 mutants represent compromised ATP synthesis in vitro, and whole-worm respiration in prmt-1 mutants is decreased in vivo Transgenic rescue experiments demonstrate that PRMT-1-dependent asymmetric arginine dimethylation is required to prevent mitochondrial reactive oxygen species (ROS) production, which consequently causes the activation of the mitochondrial unfolded-protein response. Furthermore, the loss of enzymatic activity of prmt-1 induces food avoidance behavior due to mitochondrial dysfunction, but treatment with the antioxidant N-acetylcysteine significantly ameliorates this phenotype. These findings add a new layer of complexity to the posttranslational regulation of mitochondrial function and provide clues for understanding the physiological roles of PRMT-1 in multicellular organisms.


Subject(s)
Arginine/metabolism , Caenorhabditis elegans/metabolism , Energy Metabolism , Homeostasis , Mitochondria/metabolism , Acetylcysteine/pharmacology , Adenosine Triphosphate/metabolism , Animals , Avoidance Learning/drug effects , Behavior, Animal/drug effects , Caenorhabditis elegans/drug effects , Caenorhabditis elegans Proteins/metabolism , Energy Metabolism/drug effects , Homeostasis/drug effects , Methylation/drug effects , Mitochondria/drug effects , Mitochondrial Proteins/metabolism , Mutation/genetics , Oxidative Phosphorylation/drug effects , Oxygen Consumption/drug effects , Reactive Oxygen Species/metabolism , Substrate Specificity/drug effects , Unfolded Protein Response/drug effects
12.
BMC Endocr Disord ; 16(1): 67, 2016 Nov 26.
Article in English | MEDLINE | ID: mdl-27887605

ABSTRACT

BACKGROUND: We aimed to describe the safety and efficacy of insulin glargine in Chinese paediatric patients with type 1 diabetes mellitus (T1DM). Neutral protamine Hagedorn (NPH) insulin was the reference therapy. METHODS: This open-label, randomised, Phase III study was conducted at 10 sites in China. Children aged ≥6 to <18 years with T1DM were randomised (2:1) to insulin glargine or NPH insulin asbasal insulinfor a 24-week treatment period. For all patients, insulin aspart was given as bolus insulin. The primary endpoint was absolute change in glycated haemoglobin(HbA1c) from baseline to Week 24. Secondary endpoints included the percentage of patients reaching HbA1c <7.5% (<58.5 mmol/mol), and safety. The study was registered at clinicaltrials.gov (NCT01223131). RESULTS: In total,196 patients were screened, and 162 were randomised (107 and 55 patients were randomised to insulin glargine and NPH insulin, respectively). The mean ± SD of absolute change in HbA1c was-0.25 ± 1.68% (-2.69 ± 18.32 mmol/mol) in the insulin glargine group and -0.54 ± 1.67% (-5.55 ± 20.32 mmol/mol) in the NPH insulin group. At Week 24, 18.7 and 21.6% of patients in the insulin glargine and NPH insulin groups achieved HbA1c <7.5% (<58.5 mmol/mol). Both treatments were generally well tolerated. A numerically lower rate of symptomatic hypoglycaemia per patient year was observed for insulin glargine versus NPH insulin (24.3 ± 45.8 versus32.3 ± 43.2); severe hypoglycaemia was rare (<2%). CONCLUSIONS: Initiation of insulin glargine can aid Chinese paediatric patients with T1DM to safely reduce their HbA1c levels.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Glycated Hemoglobin/metabolism , Hypoglycemic Agents/therapeutic use , Insulin Glargine/therapeutic use , Insulin, Isophane/therapeutic use , Adolescent , Blood Glucose , Child , China , Female , Humans , Hypoglycemic Agents/adverse effects , Insulin Glargine/adverse effects , Insulin, Isophane/adverse effects , Male , Treatment Outcome
13.
Biosens Bioelectron ; 82: 85-92, 2016 Aug 15.
Article in English | MEDLINE | ID: mdl-27045526

ABSTRACT

Detection and quantification of specific protein with ultralow concentration play a crucial role in biotechnological applications and biomedical diagnostics. In this paper, a label-free and enzyme-free amplified fluorescent biosensor has been developed for transcription factors detection based on AT-rich double-stranded DNA-templated copper nanoparticles (ds DNA/Cu NPs) and hairpin DNA cascade reaction. This strategy was demonstrated by using nuclear factor-kappa B p50 (NF-κB p50) and specific recognition sequences as a model case. In this assay, a triplex consists of double-stranded DNA containing NF-κB p50 specifically binding sequences and a special design single-stranded DNA (Trigger) which is able to activate the hairpin DNA cascade amplifier (HDCA). In the presence of NF-κB p50, the triplex became unstable since the target bound to the recognition sequences with strong affinity. The selective binding event confirmed that the Trigger was successfully released from the triplex and initiated HDCA to yield the product which could effectively template the formation of fluorescent Cu NPs. The experimental results revealed that the advanced strategy was ultra-sensitive for detecting NF-κB p50 in the concentration range from 0.1 to 1000 pM with a detection limit of 0.096 pM. In addition, the relative standard deviation was 4.08% in 3 repetitive assays of 500 pM NF-κB p50, which indicated that the reproducibility of this strategy was acceptable. Besides desirable sensitivity, the developed biosensor also showed high selectivity, cost-effective, and simplified operations. In addition, the proposed biosensing platform is versatile. By conjugating with various specific recognition units, it could hold considerable potential to sensitive and selective detect various DNA-binding proteins and might find wide applications in biomedical fields.


Subject(s)
Biosensing Techniques/methods , Copper/chemistry , DNA/chemistry , Fluorescent Dyes/chemistry , Metal Nanoparticles/chemistry , Transcription Factors/analysis , Humans , Limit of Detection , NF-kappa B/analysis , Nucleic Acid Amplification Techniques/methods , Reproducibility of Results , Spectrometry, Fluorescence/methods
14.
Analyst ; 140(16): 5650-5, 2015 Aug 21.
Article in English | MEDLINE | ID: mdl-26134353

ABSTRACT

Thioflavin T (ThT), as one of the most exciting fluorogenic molecules, boasts the "molecular-rotor" ability to induce DNA sequences containing guanine repeats to fold into G-quadruplex structures. It has been demonstrated to sense this change by its remarkable fluorescence enhancement. In this work, taking T4 polynucleotide kinase (PNK) as a model, the ThT/G-quadruplex based platform and λexonuclease (λexo) cleavage reaction were combined to design a label-free "turn-on" strategy for fast, simple and accurate detection of T4 PNK activity and its inhibition. In the presence of T4 PNK, the designed thioflavin T based molecular beacon (TMB) DNA probe could be phosphorylated and then digested by the cleavage of λexo, releasing the G-quartets. These then bound to ThT to form ThT/G-quadruplexes with an obvious fluorescence generation, for the "turn-on" detection of T4 PNK. In comparison to traditional methods, the proposed TMB probe is convenient, requiring no sophisticated labeling and separation processes and displaying high analytical performance. It exhibits a satisfying detection result for the activity of T4 PNK with a low detection limit of 0.001 U mL(-1). This is not only meaningful for further research on disease-related biochemical processes, but also valuable for molecular-target therapies.


Subject(s)
Bacteriophage T4/enzymology , Oligonucleotide Probes/chemistry , Polynucleotide 5'-Hydroxyl-Kinase/antagonists & inhibitors , Polynucleotide 5'-Hydroxyl-Kinase/metabolism , Fluorescence , Humans , Limit of Detection , Staining and Labeling
15.
Analyst ; 140(4): 1260-4, 2015 Feb 21.
Article in English | MEDLINE | ID: mdl-25553613

ABSTRACT

Development of strategies for the sensitive and selective detection of the folate receptor (FR) that are simple and low cost is of great importance for assessing cancer therapeutics due to its crucial role in physiological, pharmacological and pathological processes. In this paper, gold nanoparticle (AuNP)-based novel ratiometric colorimetry for the detection of the folate receptor (FR) is proposed based on terminal protection of small-molecule-linked DNA. The single-stranded DNA (ssDNA) terminally tethered to folic acid (FA) is protected from degradation by exonuclease I (Exo I) when the FA moiety is bound to FR. The hybridization between FR-protected DNA and DNA-functionalized Au NPs generated a red-to-purple colour change, allowing the visual detection of FR. The detection limit of FR can be as low as 0.33 ng mL(-1) with the naked eye. It provides a promising strategy for visual detection of the binding event of FA to its protein receptor-FR with advantages such as simplicity, high selectivity, and a wide linear range.


Subject(s)
Colorimetry/methods , Folate Receptors, GPI-Anchored/blood , Folic Acid/chemistry , Gold/chemistry , Immobilized Nucleic Acids/chemistry , Metal Nanoparticles/chemistry , DNA, Single-Stranded/chemistry , Folate Receptors, GPI-Anchored/analysis , Humans , Limit of Detection , Metal Nanoparticles/ultrastructure , Nucleic Acid Hybridization
16.
Nanoscale ; 7(7): 3300-8, 2015 Feb 21.
Article in English | MEDLINE | ID: mdl-25623467

ABSTRACT

In the present study, based on the mimic oxidase catalytic character of nucleic-acid-stabilized silver nanoclusters (DNA/AgNCs) and hybridization chain reactions for signal amplification, the fabrication of a label-free sensitive "turn-on" electrochemical aptasensor for the amplified determination of lysozyme was demonstrated. First, the designed DNA duplex was modified on the electrode. With the specific binding of the target, lysozyme and its aptamer, the lysozyme-binding DNA sequence was liberated, exposing the induced DNA sequence, which in turn triggered the formation of the supersandwich DNA structure. Because the cytosine-rich sequence was designed ingeniously on the DNA sequence, DNA/AgNCs were formed on the supersandwich DNA structure. The peroxidase-like character of DNA/AgNCs produced detectable electrochemical signals for the lysozyme aptasensor, which showed a satisfying sensitive detection of lysozyme with a low detection limit of 42 pM and a wide linear range of 10(-10) M to 10(-5) M.


Subject(s)
Aptamers, Nucleotide/chemistry , Electrochemistry/methods , Metal Nanoparticles/chemistry , Nanotechnology/methods , Silver/chemistry , Biocompatible Materials/chemistry , Biosensing Techniques , Calibration , Catalysis , DNA/chemistry , Electrodes , Equipment Design , Gold/chemistry , Humans , Hydrogen Peroxide/chemistry , Muramidase/chemistry , Nucleic Acid Hybridization , Oligonucleotides/chemistry
17.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-936960

ABSTRACT

@#Objective To explore the anti- inflammatory of pricking blood therapy in acute gouty arthritis rats. Methods 60 Sprague-Dawley rats were equally divided into normal group, bloodletting normal group, sham group, arthritis group, bloodletting group and ibuprofen group. The acute gouty arthritis model was established with injecting uric acid sodium salt into the right ankle joint cavity. The ibuprofen group was administrated with ibuprofen intragastrically, the bloodletting normal group and bloodletting group were pricked the right Kunlun (BL60) acupoint. The cross section diameter of the right ankle joint were measured before and after treatment. Levels of mRNA and protein of interleukin (IL)-10 and IL-4 expressed in ankle were determined with RT-PCR and Western blotting Results The cross section diameter increased in the bloodletting group compared with the normal group after treatment (P<0.05), and decreased (P<0.05) compared with the arthritis group and the ibuprofen group, while the expression of IL-10 mRNA increased (P<0.05) compared with the normal group, the arthritis group and the ibuprofen group, as well as the IL-10 protein compared with the normal group and the arthritis group (P< 0.05). The expression of IL-4 mRNA and protein increased without significance (P>0.05) in the bloodletting group compared with the normal group. Conclusion IL-10 may play a role of anti-inflammatory in pricking bloodletting therapy for acute gouty arthritis.

18.
Chinese Acupuncture & Moxibustion ; (12): 1143-1146, 2013.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-246974

ABSTRACT

Through retrieval of all medical journals of CNKI and VIP from Jan. 1996 to Oct. 2012, ninety-nine articles were selected and analyzed. The result shows that reliable effect can be found in pain relieving, especially in pain of muscles and soft tissues. In mechanism research, action mechanism of Fu's subcutaneous needling (FSN) on pain relieving is expounded through theory of traditional medicine and modern medicine. Although the effect of FSN on pain relieving has been confirmed by numerous clinical trials, it is still lack of explanation on mechanism revealing. The further studies should focus on mechanism expounding, improving research methods and selecting more objective and reasonable evaluation system. Therefore, the effectiveness and scientificalness of FSN can be further enhanced.


Subject(s)
Humans , Acupuncture Analgesia , Methods , Acupuncture Therapy , Methods , Pain Management , Methods , Randomized Controlled Trials as Topic
19.
Chinese Journal of Virology ; (6): 58-63, 2011.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-286078

ABSTRACT

A new viral sampling concentration device was designed which was equipped with a new cationic filter membrane-Nanoceram suitable for field sampling. Norovirus Genegroup II was detected from environmental water with the aid of this device. The effects on virus recovery of prefiltration, various second-concentration methods, and different eluants were investigated through pre-experiment. The concentration optimized process, and the optimal concentration process were then determined. The results showed that the prefiltration had a profound effect on virus recovery, and two second-concentration method: PEG-NaC1 precipitation and celite adsorption, had almost the same concentration effects. The Na2 HPO4 solution of 0.15 mol/L was selected as the final eluant to elute the adsorbed Nuorovirus from the celite. The virus recovery of Nanoceram was determined to be 3.02%. Finally, successful detection of Norovirus GII in sewage from Yangqiao River, Fengtai District, Beijing was acheived. All these data had shown that the Naneceram filter concentration method could concentrate Norovirus from environmental water with a steady effects.


Subject(s)
Filtration , Methods , Fractional Precipitation , Methods , Genotype , Norovirus , Classification , Genetics , Rivers , Virology , Water Microbiology
20.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-316981

ABSTRACT

<p><b>OBJECTIVE</b>To identification and analysis Aichi virus from diarrhea and normal children in Lanzhou, and discuss the relationship between Aichi virus and Infant Diarrhea.</p><p><b>METHODS</b>According to the literature published data, Using RT-PCR method to amplified Aichi virus 3CD fragment and the positive products were sequenced and determined, and made the alignment analysis between the nucleotide sequences of the amplified fragment with the known sequence of this virus.</p><p><b>RESULTS</b>There was 1 case detection of Aichi virus in the 46 hospitalized children with diarrhea and 299 children with diarrhea out-patients specifically, Overall detection rate was 0.06%, and there was no Aichi virus was detected in normal control children. 2 viral 3CD gene and the known reference strains of nucleotide sequences were 97%, while phylogenetic analysis showed that genotype of 2 viral belongs to the B.</p><p><b>CONCLUSIONS</b>There existed B Genotype of Aichi virus in China, and more research is needed to clarified the etiology and epidemiology of Aichi virus characteristics.</p>


Subject(s)
Child , Humans , Infant , China , Diarrhea , Virology , Feces , Virology , Kobuvirus , Classification , Genetics , Molecular Sequence Data , Phylogeny , Picornaviridae Infections , Virology
SELECTION OF CITATIONS
SEARCH DETAIL
...